package stackQueue.有效括号;

import java.util.Stack;

public class Test {
    public boolean isValid(String s) {
        Stack<Character> stack = new Stack<>();

        for(int i = 0; i < s.length(); i++) {
            char ch = s.charAt(i);
            if(ch == '(' || ch == '{' || ch == '[') {
                stack.push(ch);
            }else if(ch == ')') {
                if(!stack.isEmpty() && stack.peek() == '(') {
                    stack.pop();
                }else {
                    return false;
                }
            }else if(ch == '}') {
                if(!stack.isEmpty() && stack.peek() == '{') {
                    stack.pop();
                }else {
                    return false;
                }
            }else if(ch == ']') {
                if(!stack.isEmpty() && stack.peek() == '[') {
                    stack.pop();
                }else {
                    return false;
                }
            }
        }

        return stack.size() == 0;
    }
}
